Yeah, sure, I mentioned tells because having more information is better. The onus is on me to protect my dog from sociopaths who bring guns to shoot random dogs that walk up to them (as a reminder, that is the situation we're discussing apart from your "defense of a child" scenario)

Your dog comes up and sniffs me, fine. Slobber sucks but whatever.

But if it yelps, barks, gets territorial, bares his teeth, etc, the sociopath (ie unable to behave properly in society) is the dog owner who cant keep the dog on a leech.